Self-priming centrifugal pumps



Oct. 18, 1960 w. K. .JEKAT Erm.

SELF-PRIMING CENTRIFUGAL PUMPS Filed Deo. 6. 1957 WALER KJEKAT JOHNHDOQLIN THEODQRE Rr-:Sllg/ FIG. 2

United States Patent G SELF-PRIMING CENTRIFUGAL PUMPS Walter K. Jekat,West Orange, John H. Doolin, New Providence, and Theodore R. Esatow,Westfield, NJ., assignors to Worthington Corporation, Harrison, NJ., acorporation of Delaware Filed Dec. 6, 1957, Ser. No. 701,198

11 Claims. (Cl. 10B- 113) This invention relates generally to aself-priming centrifugal pump adapted to be operated at diiferentcapacities or heads by pre-selecting an impeller of a particulardiameter according to the capacity or head required. More particularly,this invention contemplates providing this pump with novel means forretaining the self-priming feature regardless of the diameter size ofthe impeller selected.

In order to adapt this self-priming centrifugal pump for assembly linemanufacturing techniques and to fuliill the requirements of the user; asfor example a pump capable of delivering a variety of capacities andheads and still retaining the self-priming features, it has been foundnecessary to adapt the standard casing of the self-priming centrifugalpump to accommodate impellers of varying diameters. However, with thisprovision of varying impellers the self-priming feature of the pump hasbeen seriously arrested.

The present invention overcomes the foregoing objection by providing thepump with a novel recirculation tube, having the novel prime retentioncharacteristic of the apparatus disclosed in application, Ser. No.576,442, iled in 1956, now United States Letters Patent No. 2,831,434,which is readily mounted in a pump that includes therein thepre-selected impeller providing the head and capacity required by theuser.

Specifically, the invention contemplates a novel tube, readily mountedin the pump casing, that is pre-selected to coact with a particularimpeller so that the operative relation between the tube and theimpeller will provide the rapid self-priming characteristics for thesecentrifugal pumps.

It is therefore an object of this invention to provide a novel tube vina self-priming centrifugal pump which will permit the retention of theself-priming feature in pumps adapted to operate with impellers ofvarying diameters.

It is another object of this invention to provide means .for the noveltube which maintain same in operative rela-L tion with the impeller toprovide for the retention of the rapid self-priming characteristicdemanded by the user.

It is a further object of this invention to adapt these self-primingcentrifugal pumps for assembly line manufacturing techniques.

Further objects and advantages of the invention will become evident fromthe following description with reference to the accompanying drawings,in which:

Figure 1 is a side elevation of the self-priming centrifugal pumpincluding the novel recirculation tube in section.

Figure 2 is a vertical section taken on line 2-2 of Figure l, and

Figure 3 is a vertical section showing a modified form of the invention.

Figure 4 is a part section showing a modified form of the adjustingmeans.

Referring particularly to the drawings, Figure 1 shows a self-primingcentrifugal pump, generally designated 10,

I which includes a casing 11 having a suction ,chamber 12,

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a discharge chamber 13 and an impeller chamber or volute 14 preferablyformed as integral portions of said casing. Impeller chamber 14 isadapted to receive one end of a shaft 15 which extends through a packinggland 16. An impeller 17 disposed in the impeller chamber 14 is mountedon the end of the shaft 15 by any suitable means such as threaded member18 so that the impeller is iixed to and rotatable with the shaft 15.Rotation is imparted to the shaft 15 and impeller 17 by any suitabletype of prime mover, generally designated 19, such as a gas engine whichis preferably coupled to the shaft 15 at its other respective end in anywell known manner and hence not more fully described herein. The usualfront plate 40 is mounted in the front portion of the casing and inassociation with the impeller to provide a suction inlet thereto. v

Upon rotation of the shaft 15, the impeller 17 flows iiuid from thesuction chamber 12 to the impeller chamber '14 through iiow passagemeans 20, providing communication between impeller chamber 14 anddischarge chamber 13, and then to the discharge chamber 13 for use inthe system in which the self-priming centrifugal pump .is operativelyassociated.

As is the usual practice in the art, prime on start-up is provided forby liquid that remains in the suction chamber 12 and discharge chamber13 after pump Shutdown. A reservoir characteristic is provided for inthese chambers v12 and 13 by valve means 21 which function, as is wellknown in the art and hence not more fully described, to provide for theretention of the initial prime for the pump. To provide for theretentionof the prime during pump operation and after the initial prime liquidhas been llown to the discharge chamber, the pump casing 11 is providedwith novel means, generally designated 22, which are associated inoperative relation with the impeller 17 whereby the self-primingcharacteristic is retained without regard to the diameter size of theimpeller selected for operation in the pump.

Speciiically, this novel means 22 comprises a recirculation chamber orguide means 23 formed in the casing 11 in spaced relation with theimpeller chamber 14 and includes tiow passage means 24 which providesforfluid communication between the discharge chamber 13and the impellerchamber 14. f

,Slidably disposed in the recirculation chamber 23 isa recirculationtube 25 which includes liow passage means 26 which preferably coincidewith the ow passage means 24 on the recirculation chamber 23 to providefor return flowof fluidffrom the discharge chamber 13 to the impellerchamber 14. Provision is made in the casing 11, to be hereinafterdescribed, for the retention of the leading and trailing edges 27 and28, respectively, in close clearance with the impeller 17 so that theeffect of the' eddies in the impeller chamber acting on the fluidreturning from kthe discharge chamber thereto is substantially arrested.

In order to limit the entry of the recirculation tube 25 into theimpeller chamber and to maintain the leading and trailing edges 27 and28, respectively, in close clearance with the impeller selected foroperation in the pump 10, tube 25 is provided with stop means 29 whichpreferably take the form of a shoulder which sits on a coacting stopmeans 30, preferably taking the form of a shoulder, on

`the recirculation chamber 23. It is not intended to limit theseforegoing stop means 29 and 30 to the form shown in Figure l hereinabovedescribed; it is to be understood that they may take any form whicheffectively limits and maintains the tube 25 in close clearance with theimpeller 17, as for example the form shown in Figure3 to be hereinafterdescribed.

It is evident with the provision of the compact recirculation means 22as hereinabove described, that these selfpriming centrifugal pumps arereadily adapted for as- 3 sembly line manufacturing techniques and inaddition the prime characteristic is retained with the ready insertionof a novel tube in operative position after the impeller providing therequired head or capacity has been selected.

To this 'end theyleading 'edge 27 can be 'cut back to provide smootherhow, should a small diameter impeller be 'selected for operation.

During operation of 'the pump it -is imperative .that the tube 25 bemaintained in operative relation with the impeller 17 describedhereinabove. To this end a spring member 31 or the llike is `disposed inthe recirculation chamber.23 and held in operative relation with theport 25 by a plug element 32 'associated therewith and mounted in thecasing 11 las lis shown in the drawings.

Accordingly, it is vevident that from the foregoing description that thedisclosed pump not only retains the rapid :flow rate necessary for rapidself-prirning but also discloses` a pump that is readily adapted forassembly line manufacturing technique,

In operation and after the initial prime fluid in the reservoir 12 isflown to the discharge chamber y13,

through flow'passage means 20, itis returned tree of air,

vwhich is separated Atherefrom in the `dischar-ge chamber, 4to theimpeller chamber 14 through flow passages 24 and 26 inthe Irecirculationmeans 22. r[his process keeps repeating itself until all the air isexhausted from the suction -chamber 12.

After the air is exhausted the pump continues to pump .the :duid presentthrough lthe how passage means 20 into the discharge chamber 13 where itis in `turn passed through pump outlet 33 to use or other desireddisposal.

kExcept for` the modified form of stop means generally designated 35'the construction and operation of the pump shown in Figure 3 isotherwise identical to that shown in lFigure 1 of the 4drawings anddescribed hereinabove. Thus Figure 3 `shows the stop 'means 35 as a stem30 connected Vat one end to the base portion 29' 'of the recirculationtube 25 in any menner known in the art and at its other end isthreadably received by a plug member 36' mounted in the casing 1l. Toprevent the seepage of pressurized fluid along the portion 37' of thestem threadedin the plug 36 and to prevent damage to :the Vend extendingoutwardly of thecasing 11 the stem is provided W-ithfa cap 3S"'threadably mounted thereon and in fluid 'sealing relation with the stem29' at the top`39 of plug 36'.

It will be noted that with this provision of :stop means 35 .the tube 25can be adjusted in close clearance with the impellershould there'be adisplacement of same for any reason, `such .as a wearing ofthe leadingand trailing edges of thesport '25.

'To `adjust the tube 25 the cap 38' is removed, if in the form shown inFigure `3, `and the stem 30 is manipulated to adjust the tube' in closeclearance with the impeller 17 -It is evident that the flow passagemeans 26 in the tube 25 must be yadapted to coa-ct with tlow passagemeans 24 in the event :that'the tube -is adjusted after its selectionfor operation. To this end flow passage means 26 may be oversized as isVshown in Figure 3 of the drawings.

If the cap 38 is in theform shown in Figure 4 manipulation of said capis all that is necessary to adjust the port 25 in close clearance withthe impeller, as is evident to those skilled Vin the art.

It will be understood that the invention'is not to be limited to thespecific construction or arrangement of par-ts shown b ut that 'theylmay be widely modied within the inventiondefined by the claims.

`What is 'claimed is:

1. In .a self-priming centrifugal pump comprising a casing, includingintegral therewith a suction chamber, a discharge chamber, and animpeller chamber, said impeller chamber having flow passage meansinterconnecting'said 'discharge chamber and said suction chamber,

d said impeller chamber being 4adapted to accommodate impellers of`different diameters one at a time and for iiowing fluid -from saidsuction chamber through said flow passage means to said dischargechamber, guide means in said casing providing a recirculation portiontherein in communication with said impeller chamber and said dischargechamber, -a detachable recirculation tube slidably disposed in saidguide means and having one of the ends thereof extending into saidimpeller chamber, huid passage means in said tube communicating withsaiddischarge chamber .and said impeller chamber through the recirculationportion of said guide means whereby fluid `ilown to said dischargechamber may be returned from said discharge chamber through 'saidrecirculation tube to said impeller chamber, the end of said detachablerecirculation tube extending into said impeller chamber having leading.and trailing edges in close clearance with the outer periphery of theimpeller mounted in said impeller chamber, stop means on said tube andcoacting stop means in said guide means engaging the stop means Von saidtube for maintaining the leading and trailing edges on .the end of saidtube extending into said impeller chamber in close clearance with theouter periphery of .the impeller, andmeans in said casing andoperatively associated with said recirculation port and adapted to holdsame in operating position.

2. In the self-priming centrifugal pump claimed in claim 1 wherein'thestop means on said tube comprises `a shoulder and lthe stop means insaid casing comprises a cooperating shoulder -for engagingthe shoulderon said Itube and means in said casing -for urging said shoulder on.said tube in abutment with the shoulder in said casing.

3. In the sel-fepriming centrifugal pump claimed in claim 2 whereinthemeans for urging said shoulder on said 4tube in abutment with theshoulder in said casing comprises a spring mounted in said casing and inpressing relation with the end of said recirculation tube remote from'the end extending into .the impeller chamber.

4. In a self-'priming centrifugal pump comprising a casing, includingintegral therewith a suction chamber, a discharge chamber,l and animpeller chamber, said impeller chamber having ow'passage meansinterconnecting said discharge chamber and said suction chamber, said"impeller chamber beingadapted lto accommodate impellers of diierentdiameters one at a time wherein the particular impeller Ymay vary from apredetermined minimum diameter to ha 'predetermined maximum diameterwhereby the selected impeller hows fluid Ifrom said suction chamber tosaid discharge chamber, guide means in said casing providing arecirculation portion 'therein in communication with said impellerchamber and said discharge chamber, a detachable recirculation tubeslidably disposed in said guide means and having one of 'the endsthereof extending .into said impeller chamber, -uid 'passage means insaid tube communicat- 4ing with said discharge chamber and said impellerchamber through the recirculation portion of said :guide means wherebyhuid .downto said discharge chamber may be returned :from said dischargechamber through said recirculation tube to said impeller chamber, theend of said detachable recirculation tube extending into said "impellerchamber having leading and trailing edges in prises acooperating'shoulder Vfor engaging the shoulder on 'tube Yand means insaid casing for urgingsaid shoulder on said port in abutment with theshoulder in said casing.

6. In the self-priming centrifugal pump claimed in claim 5 wherein themeans for urging said shoulder on said tube in abutment with theshoulder in said casing comprises a spring mounted in said casing and inpressing relation with the end of said recirculation tube remote fromthe end extending into the impeller chamber.

7. In a self-priming centrifugal pump comprising a casing including asuction chamber, a discharge chamber and an impeller chamber as integralportions thereof, a flow passage means in the impeller chamber forcommunicating the suction chamber with the discharge chamber beingadapted, said impeller chamber to accom-modate impellers of `differentdiameters one at a time wherein the selected impeller may vary from apredetermined minimum diameter to a predetemined maximum diameterwhereby the selected impeller flows uid from said suction chamber tosaid discharge chamber, guide means in said `casing including arecirculation portion `for communicating the impeller chamber with thedischarge chamber, a detachable recirculation tube slidably disposed insaid `guide means and having one of the ends there extending into saidimpeller chamber, fluid passage means in said recirculation tubecommunicating the :discharge chamber with the impeller chamber andthrough the recirculation portion of the guide means whereby fluid owedto said discharge chamber may be returned from said discharge chamberthrough said recirculation tube to said impeller chamber, the end ofsaid detachable recirculation tube extending into said impeller chamberhaving leading and trailing edges in close clearance with the outerperiphery of the impeller mounted in said impeller chamber, means in thecasing and operatively connected to Said recirculation tube formaintaining same in operable position relative said impeller, said lastmentoned means comprising a stem member disposed in the casing andconnected to the base of said recirculation tube at one end andadjustable means operatively connected to the other end of said stemmember for moving the leading and trailing edges of said recirculationtube relative said impeller.

8. In the self-priming centrifugal pump claimed in claim 7 wherein themeans for maintaining the recirculation tube in operable positionrelative said impeller comprises a stem member connected to the baseportion of the recirculation tube at one end and extending outwardly outof said casing at the other end, and the adjustable means beingthreadably connected to the portion of said stem extending out of saidcasing for maintaining the leading and trailing edges on the end of saidtube in close clearance with the outer periphery of lthe impeller.

9. In a self-priming centrifugal pump comprising a casing including asuction chamber, .a discharge chamber and an impeller chamber `asintegral portions thereof, a ilow passage means in the impeller chamberfor communicating the suction chamber with the discharge chamber beingadapted, said impeller chamber to accommodate impellers of differentdiameters one at a time wherein the selected impeller may vary from apredetermined minimum diameter to a predetermined maximum diameterwhereby the selected impeller ows uid from said suction chamber to saiddischarge chamber, guide means in said casing including a recirculationportion :for communicating the impeller chamber with the dischargechamber, a detachable recirculation tube slidably disposed in said-guide means and having one of the ends thereof extending into saidimpeller chamber, iluid passage means in said recirculation tubecommunieating the discharge chamber with the impeller chamber andthrough the recirculation portion of the Aguide means whereby fluid owedto said discharge chamber may be returned [from said discharge chamberthrough said recirculation tube to said impeller chamber, the end ofsaid detachable recirculation tube extending into said impeller chamberhaving leading `and trailing edges in close clearance with the outerperiphery of the impeller mounted in said impeller chamber, andadjustable means in the casing and operatively connected to saidrecirculation tube for maintaining same in operable posi-tion relativesaid impeller.

10. In a self-,priming centrifugal pump comprising a casing including asuction chamber, `a `discharge chamber Iand an impeller chamber asintegral portions thereof, a ow passage means in the impeller chamberfor communicating the suction chamber with the discharge chamber beingadapted, said impeller chamber to accommodate impellers of dilferentldiameters one at a time wherein the selected impeller may Vary from -apredetermined minimum diameter to a predetermined maximum diameterwhereby the selected impeller flows uid from said suction chamber tosaid discharge chamber, `guide means in said casing including arecirculation portion for communicating the impeller chamber with thedischarge chamber, a detachable recirculation tube slidably disposed insaid guide means and having one of the ends thereof extending into saidimpeller chamber, fluid passage means in said recirculation tubecommunicating the discharge chamber with the impeller chamber andthrough the recirculation portion of the yguide means whereby uid flowedto said discharge chamber may be returned from said discharge chamberthrough said recirculation tube to said impeller chamber, the fluidpassage means in said recirculation tube being of larger dimension thanthe recirculation portion of said `guide means, the end of saiddetachable recirculation tube extending into said impeller chamberhaving `leading and trailing edges in close clearance with the outerperiphery of the impeller mounted in said impeller chamber, means in thecasing and operatively connected to said recirculation tube formaintaining same in operable position relative said impeller, said lastmentioned means comprising a stem member disposed in the casing andconnected to the base of said recirculation tube at one end andadjustable means operatively connected to the other end of said stemmember for moving the leading and trailing edges of said recirculationtube relative said impeller.

1l. In the self-priming centrifugal pump claimed in claim 10 wherein themeans for maintaining the recirculation tube in operable positionrelative said impeller comprises a stem member connected to the baseportion of the recirculation tube at one end and extending outwardly outof said casing at the other end, and the adjustable means beingthreadably connected to the por- .tion of said stem extending out ofsaid casing tor maintaining the leading and trailing edges on the end ofsaid tube in close clearance with the outer periphery of the impeller.

References Cited in the le of this patent UNITED STATES PATENTS2,100,365 Stratton Nov. 30, 1937 2,109,804 Saxe Mar. 1, 1938 2,222,725Saxe i Nov. 26, 1940 2,291,760 Rupp Aug. 4, 1942 2,405,836 LaBour Aug.13, 1946 2,477,079 Mueller July 26, 1949 2,594,501 Ruthman Apr. 29, 19522,798,439 Longnecker July 9, 1957 2,831,434 Paashaus Apr. 22, 1958FOREIGN PATENTS 679,246 Great Britain 1-- Sept. 17, 1952 903,781 GermanyFeb. 11, 1954

